Well conduit anchoring apparatus



Dec. 5, 1961 M. B. CONRAD 3,011,558

WELL CONDUIT ANCHORING APPARATUS Filed Dec. 24, 1957 4 Sheets-Sheet 2 lia. 4'. li a 6.

Jrraemzrs.

Dec. 5, 1961 M. B. CONRAD WELL CONDUIT ANCHORING APPARATUS 4Sheets-Sheet 3 Filed Dec. 24, 1957 IN VENTOR. Men/v 48 Cam/e40 Dec. 5,1961 M. B. CONRAD WELL CONDUIT ANCHORING APPARATUS Filed Dec. 24, 1957IN VENTOR. MJPT/A/Ba 6" 0/1/240 3,611,558 WELL CGNDUIT ANCHORINGAPPARATU Martin B. Conrad, Downey, Califi, assignor to Baker Oil Tools,lne llos Angeles, Calif, a corporation of (Talifornia Filed Dec. 2.4,1957, Ser. Nix-704,925

' l9 (Ilaims. (Cl. 166-212} The present invention relates to subsurfacewell bore apparatus, and more particularly to apparatus to'be anchoredin well conduits, such as well casing and liners.

An object of the present invention is to provide anchoring apparatus tosecure a running-in string, such as a tubular string, in a Well conduit,which is relatively simple in construction, compact, and economical tomanufacture, and which is still capable of safely withstandingcomparatively high pressure differentials in the well conduit.

Another object of the invention is to provide subsurface anchoringapparatus to secure a running-in string in a well conduit, which iscapable of remaining anchored against the force of hydraulic pressuretending to shift it in a particular longitudinal direction, and .whichcan be released from anchored condition by movement of the running-instring in such particular longitudinal direction. By wayof. example, ifthe anchor withstands hydraulic pressure tending to shift it upwardly inthe well conduit, the anchor can be released by taking an upward pull orstrain on the running-in string.

A further objectof the invention is to provide subsurface anchoringapparatus whichis capable of remaining anchored in the well conduitagainst high pressure diiferentials, and which can be released from theWell conduit by the taking of a strain on the running-in string ofrelatively low magnitude.

An additional object of the invention is to provide subsurface anchoringapparatus in which a-' relatively large force is necessary to shiftparts of theapparatus from retracted to expanded positions, theforcenecessary to retract the parts from their expanded position beingrelatively small. Inadvertent setting of the'anchor in a well conduitis, therefore, avoided.

Yet another object of the invention is to provide improved anchoringapparatus to be set in a wellconduit and retained in a set condition byfluid pressure in- -ter'nally of the apparatus.

Still a further object of the invention is to provide anchoringapparatus to be set in a well conduit and retained in suchcondition byfluid pressure differential externally of the apparatus.

This invention possesses many other advantages, and

'has other objects which may be made more clearly apparent from aconsideration of several forms in which it may be embodied. Such formsare shown in the drawings accompanying and forming part of the presentspecification. These forms will now be described in detail, for thepurpose of illustrating the general principles of the invention; but itis to ,be understood that such detailed description is not to ,-be takenin a limiting sense,

since the scope of the invention is best defined by the appended claims.

Referring to thedrawings: v

FIGURE 1 is a longitudinal section through an anchoring apparatusdisposed in a well casing, with parts of the anchoring apparatus inretracted position;

FIG. 2 is a cross-section taken along the line 2-2 on FIG. 1;

FIG. 3 is a cross-section taken along the line 3 -3 on FIG. 1;

FIG. 4- is a quarter longitudinal section similar to FIG.

3,011,558 Patented Dec. 5, 1561 2 1, illustrating the apparatus anchoredin the well casing against upward movement therewithin;

FIG. 5 is an enlarged viewjof a portion of the apparatus shown in FIG.4; I

FIG. 6 is a quarter longitudinal section through another embodiment ofthe apparatus,'with the parts in retracted position;

FIG. 7 is a view similar to, FIG. 6 of the anchoring apparatus set inanchored condition against the well casing;

FIG. 8 is a View similar to FIG. 6 of still another embodiment of theinvention, with the parts in retracted position;

FIG. 9 is a view similar to FIG. 8 illustrating the anchoring apparatusanchored in the well casing;

FIG. 10 is a side elevation, on an enlarged scale, of the latchingor-coupling sleeve portion of the apparatus illustrated in FIGS. 1 to 5,inclusive;

FIG. 11 is an enlarged fragmentary section through a portion of theapparatus illustrated in FIGS. 6' and 7;

FIG. 12 is a full cross-section, on an enlarged scale, taken along theline 12- 12 on FIG. 6;

FlG. l'3is a full cross-section, on an enlarged scale, taken along theline 13-13 on FIG. 6;

FIG. 14 is a cross-section taken along the line 14-14" on FIG.-9.

in the form of invention illustrated in FIGS. 1 to 5, inclusive, and-FIG. 10, an anchor A is secured to a running-in string B, such as atubularstring extending to the top of the well bore, and is lowered in awell casing C to a desired point therein at which it is to be secured.to a body coupling 12 which is, in turn, threadedly se cured to thelower portion of an adjacent section of tubing constituting part of thetubing string B extending to the top of the well bore. Similarly, thelower end of the body may be constituted as a threaded pin 13 threadedlyattached to a coupling 14 which is, in turn,

threadedly secured to the body portion of the lower tool D, such as aset down type of well packer.

The anchor is to besecured to the well casing C against longitudinalmovement therewithin in one direction, such as in an upward direction.To accomplish this purpose, a plurality .of circumferentially spacedslips 15 are disposed around the body 10 of the tool, the slips beingcapable of being shifted between retracted and expanded positions, andof partaking of joint longitudinal movement. Thus, the upper portion ofeach slip is slidable in a slot 16 extending through the lower portionof a slip retainer ring 17 slidable on the body or mandrel 10, the sliphaving oppositely directed tongues vl8 adapted to be received withincompanion grooves 19 in the sidesof the slot. Preferably, the tonguesand grooves 18, 19 are inclined to a small extent in an upward andoutward direction, to facilitate anchoring of the slips 15 against thewell casing B, and their retraction therefrom. The lower portions of theslipshave external wickers or teeth 20 which face in an upward directionto engage andem-b'ed themselves in the wall of the well casing.

The inner surfaces 21 of the slips are tapered in an upward and inwarddirection, coacting with companion tapered surfaces 22 on an expander 23slidably mounted on the body or mandrel 10 of the tool. The slips 15 andexpander 23 are slidably splined to one another, such that theirrelative longitudinal movement in one direction will effect expansion ofthe slips 15 into anchoring engagement with the well casing, whereasrelative longitudinal movement in the opposite direction will effectpositive retraction of the slips from the well casing. Such connectionis afforded by means of oppositely directed tongues 24 on the innerportion of each slip slidable in companion grooves 25 in the expander.It is evident that the tongues 24 and the grooves 25 are inclined in anupward and inward direction to the same extent as the coengagingexpander surfaces 21, 22.

The slip ring 17 is movable upwardly on the body 10 of the tool to theextent limited by its engagement with the lower end of the body coupling12. Its downward movement relative to the body is determined by its.engagement with an upwardly facing body shoulder 27. The slip ring 17and, consequently, the slips 15, on the one hand, and the expander 23,on the other hand, are normally urged in directions away from each otherto tend to retain and place the slips in their retracted positions byspring means 28 acting between the slip retainer ring 17 and theexpander 23. As disclosed, longitudinally extending, circumferentiallyspaced helical compression springs 28 are arranged between the slips 15,the upper ends of the springs being disposed Within sockets 29 in theslip retainer ring and bearing against the upper portions of the socket.The springs 28 are tclescoped over longitudinal centering pins 30fitting within bores 30' in the expander, with the lower ends of thesprings bearing against the upper end of the expander. It is evidentthat the springs 28 tend to shift the slip retainer ring 17 and slips 15in an upward direction relative to the expander 23, such that theinclined tongue and groove connection 24, 25 between the slips andexpander tend to hold and return the slips in a retracted position.However, when the expander 23 is shifted upwardly relative to the slips,the latter are urged in a radial outward direction to place theirwickers 2% in anchoring engagement with the wall of the well casing C. I

Depending from the expander 23 is a cylinder sleeve portion 31 of ahydraulic cylinder 32, which is spaced from the mandrel 19 of the toolto provide an annular cylinder space 33 therebetween in which ahydraulicallyactuatable latch or coupling sleeve member 34 is disposed.Actually, the lower portion 23a of the expander may be considered toconstitute an annular cylinder head, which is disclosed as beingintegral with the depending cylinder skirt 31, although it is evidentthat, if desired, the head and skirt may be made separate from oneanother and suitably secured together, as by welding or threading.

The latch or coupling sleeve 34 includes an intermediate annular pistonportion 35 which is slidable along the periphery of the body it), andalso along the lower inner wall portion 36 of the cylinder. The pistonportion 35 is always disposed below one or a plurality of fluid inletports 37 establishing communication between the central passage 33through the body and the annular cylinder space 33 between the body 10and the cylinder 32 above the piston. Leakage of fluid in an upwarddirection from the cylinder space 33 is prevented by a suitable sideseal, such as a rubber or rubber-like O ring 39, disposed in an internalgroove 4ft in the cylinder head 2311 or expander and slidably sealingagainst the periphery of the body. Leakage of fluid in a downwarddirection from the annular cylinder space 33 is prevented by an innerside seal ring 4-1, such as a rubber or rubber-like ring, disposedwithin an internal groove 42 in the piston and slidably sealing againstthe periphery of the body below its ports 37. Leakage of fluid betweenthe periphery of the piston 35 and the adjacent cylinder wall 36 isprevented by a suitable side seal ring 43, such as a rubber orrubber-like 0 ring, disposed in a ring groove 44 in the piston andslidably sealing against the cylinder wall.

When fluid under pressure differential enters the cylinder space 33 fromthe interior of the body and through the ports 37, such pressure tendsto shift the cylinder 32 and expander 23 in an upward direction, atfirst shifting the slip retainer ring 17 into engagement with the lowerend of the coupling 12, which functions as a stop, the expander 23 thenmoving upwardly along and behind the slips 15 to expand them radiallyinto anchoring engagement with the wall of the well casing C. However,it is desired that a substantial pressure differential be requiredbefore the expander can move upwardly to effect outward expansion of theslips. Accordingly, relative movement between the expander 23 and thebody it? of the tool is at first precluded by a releasable retainerdevice 45 acting between the coupling sleeve 34- and the cylinder skirt31.

in addition, it is desired that the body or mandrel 10 be directlycoupled to the expander 23 after the slips 15 havebeen expanded intoanchoring engagement with the wall of the well casing C, such thathydraulic forces acting on the body from below the anchor A will betransmitted directly from the body 10 to the expander 23, and throughthe slips 15 to the wall of the well casing.

Both the aforenoted releasable retainer feature and di-' recttransmission of upward thrust are accomplished in the present instanceby forming the lower portion of the latch or coupling sleeve 34 withdepending spring-like feet 46, which are produced by cutting a pluralityof circumferentially spaced slots 47 through the lower portion of thesleeve or member 34 to the region of the intermediate annular piston 35.These spring-like legs (i6 terminate in,

outwardiy directed foot portions 48 which are initially located in aninternal circumferential groove 49 in the lower portion of the cylindersleeve 31. The lower outer end 51; of these feet are tapered in aninward and downward direction, engaging a companion tapered surface 51defining the lower end of the internal groove 49. Any

tendency for the cylinder 32 to shift upwardly with respect to thesleeve34 causes the inclined cam surfaces 59, 5 1 to coengage and tend toshift the feet 43 inwardly out of the groove 49. The spring-like legs 46and feet 48 resist such inwardly directed forces. However, when theforces are suflicient, the spring legs 46 will be deflected inwardly tothe extent in which the foot portions 43 are removed from the groove 49.

The force to effect such inward shifting of the spring legs 46 and feet455 is provided by the pressure differential within the annular cylinderspace 33, which acts downwardly upon the annular piston 35. Suchdownward movement is not only resisted by the necessity to shift thespring feet 48 out of the groove 49, but also by virtue of upwardlyextending arms 52 forming the upper portion of the latch or couplingsleeve 34, which are produced by longitudinal slots 53 opening throughthe upper end of the sleeve and extending downwardly to the region ofthe annular piston 35. These arms 52 terminate in inwardly directedthrust heads or elements 54 having inner, lower carn surfaces 55tapering in an upward and inward direction and coacting with companiontapered surfaces 56 on an expander and lock portion 57 integral with thebody lil. After the latch or coupling sleeve 34 has shifted downwardly,or, conversely, the cylinder 34 and expander 23 have been shiftedupwardly hydraulically, for the purpose of removing the feet 48 from thegroove 49, (which will then allow the expander 23 to move upwardlybehind the slips 15 to expand the latter into anchoring engagement withthe well casing), the pressure within the cylinder is acting on thepiston '35, urging the coupling sleeve 34 downwardly, the coengagingthrust head and expander surfaces 55, 56 overcoming the elasticity orresiliency of the spring arms 52 and shifting them laterally outward tothe extent determined by engagement of longitudinally extending teeth 58on the arms with companion teeth 59 formed in the inner wall of theupper portion of the cylinder sleeve 31. When such teeth 58, 59 coengageas a result of outward expansion of the spring-like arms 52 and thrustheads 54, the expander surfaces 55, 56 are still engaged, and the body163 and cylinder sleeve 31, as well as the expander 23 integral with andsecured to thelatter, are directly coupled to one another, any upwardlydirected forces on the body 10 being transmitted through the bodyexpander 57 and thrust heads 54 to the cylinder sleeve 31 and expander2-3, the expander. being wedged behind the slips 15 to transmit suchforces through the latter to the well casing or corresponding wellconduit C.

When the pressure differential within the cylinder '32 is relieved, thehydraulic force acting downwardly on the annular piston 35 is alsorelieved, which permits the arms 52 and the thrust heads 54 toinherently return to their retracted positions, such as disclosed inFIG. 1.

As described above, the latch sleeve 34 can only'rnove to a limitedextent downwardly with respect to the body 10, as determined by outwardexpansion of the arms 52 and the engagement of their teeth 58 with thecompanion teeth 59 in the cylinder Wall. Upward movement of the latch orcoupling sleeve 34 along the body 10 is also limited, to retain theheads 54 in position for engagement with the expander and lock surface56 on the body It), by an external flange 6% on the body disposedimmediately above the heads 54. Similarly, downward movement of theexpander 23 along the body It? and the latch or coupling sleeve 34 islimited by engagement of a downwardly facing cylinder shoulder 61 withthe upper end of the annular piston 35. The full retraction of the slips15 against the body or mandrel 10 of the tool will also limit thedownward movement of the expander 23 and cylinder 32 along the body 10,by virtue of the inclined tongue and groove interconnection 24, 25between the slips 15 and the expander 23.

For the purpose of facilitating assembly of the coupling sleeve 34 onthe body 10 with its thrust heads 54 disposed between the expander andlock surface 56 and the fian e 69 thereabove, the expander and lockportion 57 is provided with slots 62 having a circumferential or arcuateextent corresponding to the circumferential extent of each arm 52 andhead 54. tween the body slots 62 are the circumfcrentially spacedexpander and lock portions 5'7, which correspond in arcuate extent withthe slots or spaces 53 between the arms 52. r

his to be noted that the interrupted expander and lock portion 57 of thebody has a substantially larger external diameter than the body portiontherebelow. In assembling the latch or coupling sleeve 34 on the body,

, the latter is inserted over the lower portion of the body it with thearms 52 and thrust heads 54 aligned with the slots 62 between theexpander and lock portions 57. The thrust heads 54 are then insertedthrough the slots 62 until the thrust heads 54 are disposed between theexpander surface 56 and the flange 6i? thereabove, whereupon thecoupling sleeve 34 is turned with respect to the body 10 to place thethrust heads in alignment with the expander and lock elements 57, theheads 54 then being disposed above these latter elements. The latch orcoupling sleeve 34 is retained properly aligned or oriented with respectto the expander and lock elements 57 by means of an orienting screw 63threaded into the body 10 between a pair of adjacent thrust headportions 54. This screw 63 will prevent substantial angular shifting ofthe thrust sleeve 34 on the body and will insure the proper engagementbetween the thrust head surfaces 55 and the expander and lock surfaces56.

In one manner of using the anchoring apparatus, the lower portion of itsbody llt) may be secured to the lower tool D, such as a set down packer,and its upper portion to the tubular string B, by means of which theentire apapratus is lowered in the well casing C, or similar conduit, tothe location at which the apparatus is to be used. During such loweringaction, the parts occupy the relative positions illustrated in FIG. 1,in which the helical springs 28 tend to hold the slips and expander 23in their relative separated condition,

the slips being retracted and the feet 48 of the releasable retainerportion of thev coupling sleeve 34 disposed in the internal groove 49,so as to prevent upward movement of the expander23 relative to theslips15. At this time,'the thrust heads .54 are disposed in their retractedposition with respect to the cylinder 32 and lock portions 57 of themandrel or body 10 of the tool.

After the apparatus has reached the location at which the anchor A is tobe set against the well casing C, the

lower tool D may be set therewithin, as by suitably manip- H ulating thetubular string B, such motion being transmitted through the body 1010the lower tool. lower too-l includes slips, an expander and a packingstructure, the slips being expanded against the well casing by imposinga downwardly directed weight on the tubular string B. After the slipsare expanded, the packing structure of the lower tool (not shown) issealed off against the wall of the well casing. Fluid under pressure maynow be pumped through the tubular string B, passing through the body 10of the tool A and through the lowertool D. For example, a formationfracturing operation may be performed. Such fluid under pressure willact through theports 3'7 and be imposed on the fluid in the annularcylinder 33-, urging the coupling sleeve 34 in a downward direction andthe cylinder 32 and expander 23 connected therewith in anupwarddirection. However, movement of the piston 35 in a downwarddirection is precluded by the spring action of the arms 52 and thethrust heads 54 engaging the expander and lock portion 57 of body ormandrel it whereas,

movement of the expander and cylinder in an upward direction is resistedby engagement of the lower tapered side 51 of the groove 49 with thecompanion tapered ends 59 of the releasable retainer sleeve 34. vWhenthe pressure differential in the cylinder 32 exceeds the resisting forceof the spring legs 46 and their feet 48, the latter are carrnnedinwardly, which then permits the fluid pres,

sure to shift the cylinder 32 and expander 23 upwardly, such actioncarrying the slips '15 and slip retainer ring 17 upwardly until the slipretainer ring engages the stop coupling 12. The expander 23 then movestoward the clip retainer ring 17 against the force of the springs 23,compressing the latter and moving up along the slips 15 to expand themlaterally outward, until they are en aged with the well casing C. 'Asthe pressure increases, the expander 23 is wedged more firmly behind theslips '15, to hold them anchored against the wall of the well casing.

During such increase in pressure, the piston 35 is moving downwardlyrelative to the body 1% and the cylinder 32, the thrust heads 54shifting down along the expander and lock surfaces 56 and laterallyoutwardly until the teeth 58 .on the arms 52 are meshed with theinternal teeth 59 in the cylinder sleeve 31 (FIG. 4). within thecylinder 32 is constantly urging the piston 35 and the complete couplingsleeve 34 in a downward direction, to hold the arms 52. in full meshwith theteeth 58 of the sleeve 31. Such pressure is .also acting in anupward direction on the cylinder head 23a and expander 23, to hold thelatter wedged behind the slips 15. The same pressure is actingin anupward direction over the lower tool 1), such as a set down type ofpacker, and is tending to shift it in an upward direction. Such upwardshifting force is transmitted through the body it) of the tool A to theexpander and lock members 57, and through the latter to the thrust heads54, which are meshed with the teeth 5? on the cylinder sleeve 31, theforce being transmitted through the cylinder sleeve and expander 23 tothe slips l5, and thence to the casing C. Accordingly, there is a directtransmission of the hydraulic forces below the tool A, and tending toshift the body 10 of the tool in an upward direction, through theexpander 23 and slips 15 to the casing C, preventing upward movement ofthe apparatus, the equipment being anchored against such upwardmovern'ent.-

Usually such The pressure In the event the anchoring apparatus A is tobe released from the well casing, the internal pressure in theapparatus, as well as the pressure below the lower tool D, is relieved.When the pressure differential within the tool drops below a forceequivalent to that of the helical springs 28, the latter can shift theexpander 23 and cylinder 32 downwardly relative to the slips l and thebody 19 of the tool, the teeth 59 on the cylinder bearing against theteeth 5'8 on the arms 52 and thrust heads 54 and camrning the latterinwardly, so that the cylinder 32 can,

in effect, ratchet downwardly along the coupling sleeve 34 until thelower tapered end 65 of the cylinder, which diverges in a downwarddirection, engages companion tapered surfaces lid on the upper portionsof the feet 48, to cam the spring legs 45 inwardly until the feet areopposite the internal groove 45), whereupon the legs and feet caninherently spring outwardly to their initial condition, in which thefeet 43 are again located in the groove 49 to releasably retain or lockthe cylinder 32 and expander 23 with respect to the body or mandrel ill?of the tool (FIG. 1). The apparatus A can now be moved longitudinally inthe well casing C and may, if desired, he removed completely therefrom.

If, for some reason, such as the presence of foreign material in thecylinder 32 or other portions of the apparatus, the springs 28 areincapable of returning the anchoring apparatus to a retracted condition,such condition can be achieved in a mechanical fashion. in the form ofdevice illustrated in FIGS. 1 to 5, inclusive, and the taking of anupward pull on the tubular string B and the body ltl of the tool willresult in a retraction of the slips l5 from the well casing, despite thefact that the slips normally anchor the tool in the well casing againstupward movement therewithin.

The angle R that the tapered surfaces 55, 2'56 on the expander 57 andthrust heads 54 makes to the axis of the apparatus is substantiallygreater than the angle S that the surfaces of the coengaging teeth 52makes to the axis of the apparatus (PEG. 5, particularly). By way ofexample, the surfaces 55, 5'6 on the expander 57 and the thrust heads '5may make an angle R of about 30 degrees to the vertical, whereas thetooth surfaces may make an angle S of about degrees to the vertical.With this relative angular relationship, the engaging surfaces of theteeth may be considered to be retractor surfaces, since they can effectretraction of the thrust heads 54, as described hereinbelow.Accordingly, following relieving of the pressure diiferential in theapparatus, and with the slips 15 in anchored position against the wellcasing, such as disclosed in FIG. 4, an upward strain may be taken onthe tubular string B and the body r mandrel iii of the tool. Such upwardpull is transmitted through the expander 57 to the thrust heads 54, andfrom the latter through the coengaging teeth 5d, 59 to the cylinder 32and expander 23, the force passing from the expander 23, through theslips 15 to the well casing C. inasmuch as the angle of inclination S ofthe tooth surfaces to axis of the tool is substantially less than theangle R of the expander and thrust head surfaces to the axis of thetool, a much greater lateral force component is being exerted betweenthe cylinder teeth 59 and arm and thrust head teeth 58, tending to shiftthe arms 52 and thrust heads 54 inwardly, than is being exerted betweenthe expander E7 and thrust heads 54, tending to shift the thrust heads54 and arms 52 outwardly. The result of the relative angularrelationship between the parts is that the taking of a sufficient upwardpull on the tubular string B and the body 19' will cause the coengagingteeth 58, 59 to pinch, retract or cam the arms 52 and thrust heads 54inwardly out of engagement with the cylinder teeth 5?, so that the body10 of the tool and the arms 52 and heads 54- can then move upwardlyrelative to the expander 23, slips 15 and slip ring 17. Such upwardmovement will occur until the body shoulder 27 engages the slip retainerring 17, after which a continuation of the upward pull will cause thebody to move the slip retainer ring 17 and the slips 15 coupled theretoupwardly relative to the expander 23, effecting a retraction of theslips 1% with respect to the expander 23, in view of the inclinedslidable tongue and groove connection 24,. 25 therebetween. Actually, itmay only be necessary for the shoulder 27 to engage the slip retainerring 17 and move the slips 15 a slight distance to disengage them fromthe well casing, after which the springs 23 become effective to shiftthe expander 23 downwardly relative to the slips 15 and the body 16 ofthe tool back to its initial position, such as disclosed in FIG. 1, inwhich the parts of the tool are again releasably retained in theirretracted conditions.

Although the anchoring apparatus has been described in connection withthe use of the lower tool D, it can be used alone to anchor the tubularstring C in the Well casing. The tubular string can be maintained intension, provided a sufiicient pressure differential is within the tool,such that the imposition of a relatively high tensile strain will notcause the teeth 58, 59 to force the arms 52 and heads 54 in an inwarddirection to release the body in of the tool from direct coupling withthe expander 23.

In the form of invention illustrated in FIGS. 6, 7, 12 and 13, ananchoring apparatus E is disclosed which is capable of functioning inessentially the same manner as in'the embodiment previously describedand of accomplishing the same purposes. The slip retainer ring 17, slips15, and expander 23 arrangement is essentially the same as illustratedin FIGS. 1 to 5, inclusive, except that the springs 28 are not providedbetween the slip retainer ring and the expander. Instead, the springforce is exerted between the cylinder sleeve portion 31a of the cylinder32a, which is threadedly secured to the cylinder head 23b, or lowerportion of the expander, and the body 10a of the tool. Moreover, adiiferent releasable retainer device is illustrated for precludinginadvertent shifting of the anchoring apparatus to a set positionagainst the well casing.

As shown in the drawings, they lower portion of the cylinder skirt 31ahas an inwardly directed flange or read 7% adapted to engage the lowerend of a split, contractile ring or retainer 71, which may havecircumferentially spaced, longitudinally extending grooves 72 in itsperiphery, to increase the flexibility of the ring.- This ring 71 fitspartly within a circumferential groove 73, in the body or mandrel ltlaof the tool, its outer portion engaging the flange 76, as abovedescribed. The upper side 74 of the groove 73 is tapered in an upwardand outward direction, engaging a companion tapered surface 75 on theupper inner corner of the ring 71 (FIG. 11). The upper outer corner '76of'the ring is tapered in an upward and inward direction, engaging acompanion tapered surface 77 on a spring seat 'or ring 73, against whichthe lower end of a helical compression spring 79 bears, the upper end ofthis spring bearing against a body spring seat 80, consisting of a solidring 81 engaged by the spring fitting Within an external recess 82 in atwopicce ring 83 mounted within a circumferential groove 24 in the body.The solid ring 82 will hold the twopiece ring 83 in the groove 84, thespring force being transmitted through the solid ring 82 and thetwo-piece ring to the body or mandrel 10a of the tool E.

An expander and lock element 57a is disposed on the exterior of the body10a and rests upon the two-piece ring 83. This expander and lock has anexpander surface Sa tapering in an upward and inward direction, engagingcompanion tapered surfaces 55a on thrust heads 54a formed at the lowerportions of arms 52a integral with an annular piston 35a slidable in thecylinder space 33a formed between the cylinder skirt 31a and the bodylila of the tool. The arms 52a and thrust heads 54a are defined betweencircumferentially spaced longitudinally extending slots extending fromthe lower end. of the latch or coupling sleeve 34a to the annular pistonportion 35a an inward position. 58a thereon adapted to engage companioninternal teeth inthe cylinder skirt'ila initially positioned therebelow.i v} As in the other form of the invention leakage of fluid from thecylinder space 33:: is prevented by a suitable side seal ring 39amounted in the cylinder head 23b and a engaging the periphery of thebody 10a above the body inlet ports 37a. A side seal ring 41a is mountedin the piston 35a and engages the periphery of the tool body ltla belowthe inlet ports 37a, while another side seal ring 43a is mounted on thepiston and engages the cylinder wall 36a. An additional seal 96 may alsobe provided to insure against leakage through the threaded connection 91between the cylinder head 23b and the cylinder sleeve 31a.

In the use of the apparatus illustrated in FIGS. 6, 7, 12 and 13, theparts initially occupy the position shown in FIG. 6, in which the splitretainer ring 71 is fitting within the body groove 73 and provides aspring force, in addition to that furnished by the helical spring 79,resisting upward movement of the cylinder 32a and expander 23 along thebody like and slips 15. After the apparatus has been run in the wellcasing to the desired point of use therewithin, the increase of thefluid pressure in the body 100 of the tool, ports 37a, and the cylinderspace 33a to a suflicient extent will exert an upward force on thecylinder 32a and a downward force on the piston 35a, sliding the latchand coupling sleeve 54:: downwardly, but with its teeth 58a engaging thesmooth periphery of the cylinder wall 36a above the cylinder teeth 5%.The upward force on the cylinder 32a is transmitted through its flange7t) to the'split retainer ring 71, and from the inclined upper surface75 of the latter to the body 10a of the tool.

When the fluid pressure becomes sufficiently high, the spring force ofthe split ring 71 tending to hold it in retracted position is overcome,the inclined surfaces 74, 75 expanding the ring and camming it out ofthe groove 73, whereupon the expander 43 and cylinder 32a can moveupwardly, being resisted only by the force of the helical compressionspring 79, which is much less than the force required to expand thesplit contractible ring 71 out of the groove 73. The cylinder 32a,expander 23, slips i5, and slip retainer 17 move upwardly until theretainer ring 17 engages the body coupling 12, after which the expandermoves upwardly relative to the slips to expand them radially intoanchoring engagement with the wall of the well casing C. During suchupward movement of the expander 23 and its cylinder 32a, the splitcontractible ring 71 merely slides along the periphery of the body Weabove the groove, 73, exerting very little resisting force to upwardmovementof the parts in expanding the slips 15 into anchoring engagementwith the well casing. During the movement of the cylinder 32a in a slipexpanding direction, its teeth 59a will ratchet over the companion teeth58a. on the thrust heads 54a, andwhen the slips 15 have been anchoredagainst the well casing, the cylinder teeth 59a and the thrust headteeth 58a will be coengaged, the expander and lock 57a on the bodyengaging the thrust heads 54:: to maintain such engagement.

As the pressure continues to increase, it urges thecylinder 32a andexpander Z3 upwardly, to holdthe slips15 more firmly anchored againstthe well casing. At the same time, the fluid pressure isactingdownwardly on the coupling sleeve 34a to hold it solidly wedged between the expander and lock 57a on the body and the cylinder 32a. Anytendency for the body 10a to move upwardly is resisted, since suchupward force is transferred through the two-piece ring 83, expander 57aand thrust heads 54a to the cylinder sleeve 31a and expander 23, therebeing a direct mechanical connection therebee to tween wedging theexpander 23 more firmly behind the slips 15 (FIG. 7). in the event theanchoring apparatus is to be released from the well casing, the pressuredifferential need merely be relieved, which will allow the spring 79 toexpand and urge the cylinder 32a and expander 23 in a down warddirection relative to the body 1011. Such, downward movement can takeplace without any substantial resistance offered by the splitcontractile ring 71, other than its sliding friction along the peripheryof the body, until the expander 23 and cylinder 32a have been moveddownwardly to substantially their full extent, in which the splitcontractile ring 71 will snap back into the companion body groove 73. Atthis time, the slips 15 will then have fully retracted from the wellcasing C, permitting the apparatus to be Withdrawn therefrom, ifdesired. In the event the parts do not move to their retracted position,then the taking of an upward pull on the tubular string C and body 19aof the tool will cause the arms 52a and thrust heads 54a to be pinchedinwardly by the coengaging cylinder threads 5911 and thrust head threads58a, the body 10a moving upwardly until the shoulder 27 differentialbeing imposed within the tool to overcome the spring force of thecontractile ring 71 and the force of the helical spring 79. Suchcombined spring forces are far greater than that oitered by the'helicalspring 79 itself. Accordingly, the helical spring can shift theanchoring apparatus to a retracted position against relatively lightresistance, whereas the hydraulic pressure can only effect a shifting ofthe slips 15 to an anchored position against a comparatively greatresistance, thereby preciudin relatively small pressure ditferentialsfrom effecting a setting of the tool in the well casing.

The anchoringapparatus illustrated in FIGS. 8 and 9 is specificallydesigned to prevent downward movement of the apparatus F relative to thewell casing C, rather than its upward movement. In addition, it isanchored against the well casing in response to pressure differential-sin the annulus H between the tubular string and the well casing, ratherthan as a result of a pressure differential internally of the apparatus.It will also resist downward movement of the tubular string and body ofthe tool within the well casing. i I

As disclosed, the lower slip retainer ring 17a is slidably mounted onthe tubular body 1% of the tool, there being lower slips 15a slidablycoupled to this retainer ring 1701 and having their wickers or teeth2dr: facing in .a downward direction, so as to be anchored. to the wellcasing against downward movement therewithin. The slips 15a are slidabiycoupled to an expander 23d, the companion tapered surfaces 21, 22between these parts being inclined in a downward and inward direction.The

expander 23d is threadedly secured to the sleeve 31b of a cylinder 32b.The upper portion 23a of. the expander may be considered to be a lowercylinder head. -,The cylinder sleeve 31b extendsupwardly along the bodyand terminates in an inwardly directed flange 7% slidable on beinglocated on the body below the body side ports 37b,

its downward; movement being limited by engagement with a body flange162. This piston 35b forms part of a latch or coupling sleeve 34b, whichis similar to that disclosed in FIG. 6, except that the sleeve isinverted. It includes the circumferentially spaced spring-like arms 52bintegral with thrust heads 5412 having external teeth 58b adapted toengage companion teeth in the cylinder sleeve 31b, the tapered surfaces55b of the thrust heads engaging a companion tapered surface 56b on anexpander ring 5712 hearing against the lower end of a two-piece ring 3afitting within a peripheral groove 84a in the body b. The two-piece ring83a is held in the groove by a solid ring 81:; disposed in a recess 82ain the former, this solid ring being engaged by a split expansiblespring ring 105 which initially extends within'an internal groove 186 inthe cylinder sleeve 31b. This spring ring 105 has an upper taperedsurface 107 inclined in an upward and inward direction for engagementwith a companion tapered surface 168 at the upper side of the shouldergroove 106. The split ring m5 engages a spring seat 199, against whichbears the lower end of a helical compres sion spring 110, the upper endof which bears against the cylinder flange 70a.

As assurance that the pressure differential in the tub ing-casingannulus H can act in an upward direction on the piston 3512, a pluralityof inlet ports 111 may be provided in the cylinder skirt below thepiston. The usual working clearance between the expander 23d and thebody ltlb of the tool should provide for the entry of fluid from thetubing-casing annulus H into the cylinder 32b and below the piston 35b,but the inlet ports 111 offer assurance that such fluid pressure will bepresent. Accordingly, the fluid under pressure in the tubing-casingannulus H is acting in an upward direction on the annular piston 35b andis acting in a downward direction on the cylinder 3% and the expander23d, the cylinder flange 7&1 actually constituting an upper cylinderhead over which the fluid pressure acts.

Fluid from the exterior of the apparatus is prevented from entering thecylinder space 3312 between the flange 76 a and piston 35!) by the sealrings 41, 43 on the piston engaging the body ltib and the cylinder skirt31b, and by the aforementioned seal 1% in the flange or head 7tla'engaging the periphery of the body.

In the use of the apparatus illustrated in FIGS. 8 and 9, the parts areinitially in their retracted position disclosed in FIG. 8, in which thethrust heads 54b and arms 52b are retracted, the split retainer ring resbeing disposed in its groove 1%. The apparatus is lowered in the wellcasing to the desired setting point, after which the pressure in thetubing-casing annulus H is increased. This pressure will act in adownward direction over the crosssectional area of the cylinder flangeor head 70a, tending to urge it in a downward direction. Such downwardmovement and corresponding downward movement of the expander 23d is atfirst prevented by the split ring 195 and also by the helicalcompression spring 110. However, when the pressure exceeds the force ofthe split ring 195, the inclined or cam surfaces m7, 108 shift the ringinwardly out of the groove 1%, the cylinder 32b and expander 23d thenmoving downwardly along the body 16b, the slips a and slip ring 17a alsomoving downwardly until the slip retainer ring engages the lower bodycoupling 12a, after which continued downward movement of the cylinderand expander will shift the expander 23d down along the slips 15a andthe latter radially outwardly into anchoring engagement with the wellcasing C. At this time, the split retainer ring 105 merely slidesrelatively freely along the inner cylindrical wall of the cylindersleeve 31b.

The external pressure differential is also acting in an upward directionover the piston portion 35b of the latch or coupling sleeve 34b, andwill shift it upwardly along the body 1% to cause the body expander 57bto cam the thrust heads 54b outwardly, until the head teeth 58b arefully meshed with the companion teeth 5% on the cylinder sleeve 31b. Asolid abutment is then formed between the body 10b of the tool and theexpander 2365 through which downward forces or thrust on the body aretransmitted to the slips 15a. Thus,'the downward forces will betransmitted from the body llila, through the two-piece ring d3a, to theexpander and lock ring 5712, and from the latter through the thrustheads 54-!) to the cylinder sleeve 31b, such downward t'orce passingfrom the cylinder sleeve through the expander 23d to the slips 15a, andthence to the well casing C.

When the apparatus is to be released from the well casing, the pressuredifferential in the tubing-casing annulus H is relieved, which willallow the compression spring fill to expand, shifting the cylinder 32band expander 23d upwardly, the cylinder sleeve 31b ratcheting past thethrust heads 54b until the split retainer ring again enters the groove1%. During such upward movement, the expander 23d is moved upwardlyrelative to the slips 15a, the tapered tongue and groove interconnection24, 25 between these parts effecting a full retraction of the slips 15afrom the well casing back to their initial position disclosed in FIG. 8.

f the spring 119 is incapable of retracting the slips 1511, as, forexample, due to some foreign material in the well casing, the fluidpressure need merely be relieved and a downward force imposed on thetubing string and the body ltlb of the tool connected thereto. The sameaction will occur on the thrust heads 54b as occurs in the other formsof the invention. The substantially lesser angle to the vertical of thecoengaging tooth faces 58b, 5% as compared to the angle to the verticalbetween the mengaging expander and thrust head surfaces 56, 55b willcause the thrust heads 54b to be cammed inwardly from the cylinder,allowing the body 10b to move downwardly to the extent suflicient tobring its lower body shoulder 27b into engagement with the slip retainerring 17a, exerting a downward pull on the slips 15a relative to theexpander 23d and effecting their retraction.

The inventor claims:

1. In apparatus to be disposed within and anchored to a well conduit:body means; slip instrumentalities carried by said body means andadapted to engage the well conduit to anchor the body means therewithin;expander means slidable along said body means and adapted to coact withsaid slip instrumentalities to expand and hold said slipinstrumentalities against the well conduit; means. for relativelyshifting said expander means and slip instrumentalities to expand saidslip instrumentalities. against the well conduit; means for transmittinglongitudinal force directly from said body means to said expander meansincluding a coupling member, first coengageable cam means on said bodymeans and coupling member tending to urge said coupling member laterallyoutwardly in response to relative longitudinal movement between saidbody means and coupling member, second coengageable cam means on saidcoupling member and expander means tending .to urge said coupling memberlaterally inwardly in response to relative longitudinal movement betweensaid expander means and coupling member, said first and second cam meansbeing so constructed and arranged that one of said cam means exerts agreater lateral force than said other cam means to release said couplingmember from one of said means in response to a longitudinal forceimposed on one of said means.

2. In apparatus to be disposed within and anchored to a well conduit:body means; slip instrumentalities carried by said body means andadapted to engage the well con duit to anchor the body means.therewithin; expander means slidable along said body means and adaptedto coact with said slip instrumentalities to expand and hold said slipinstrumentalities against the well conduit; means for relativelyshifting said expander means and slip instrumentalities to expand saidslip instrumentalities against the well conduit; means for transmittinglongituaoiijees ber, said expander means and coupling member havingsecond coengageable tapered surfaces tending to urge said couplingmember laterally inwardly in response to relative longitudinal movementbetween said expander means and coupling member, the angle of one ofsaid coengageable tapered surfaces to the axis of said body means beingsubstantially different than the angle of said other comgageable taperedsurfaces to the axis of said body means to release said coupling memberfrom one of said means in response to longitudinal force imposed on oneof said means.

3. In apparatus to be disposed within and anchored to a well conduit:body means; slip instrumentalities carried by said body means andadapted to engage the well conduit to anchor the body means therewithinagainst longitudinal movement in one direction; expander means slidablealong said bodymeans and adapted to coact with said slipinstrumentalities to expand and hold said slip instrumentalities againstthe well conduit; means for relatively shifting said expander means andslip instrumentalities to expand said slip instrumentalities against thewell conduit; means for transmitting.longitudinal force directly fromsaid body means to said expander means including a coupling member,first coengageable cam means on said body means and coupling membertending to urge said coupling member laterallyoutwardly in response tomovement of said body means in said one direction, second coengageablecam means on said coupling member and expander means tending to urgesaid coupling member laterally inwardly in response to longitudinalmovement of said body means in said one direction, said first and secondcam means being so constructed and arranged that one of said cam meansexerts a greater lateral force than said other cam means to release saidcoupling member from one of said means in response to a force exerted bysaid body means in said one longitudinal direction. t t

4. in apparatus to be disposed within and anchored to "id- I said slipinstrumentalities against the well conduit; means for relativelyshifting said expander means and slip instru mentalities to expand saidslip instrumentalities against the well conduit; means for transmittinglongitudinal force directly from said body means to said expander meansincluding a coupling member, said body means and coupling member havingfirst coengageable tapered surfaces tending to urge said coupling memberlaterallyoutwardly in response to relative longitudinal movement betweensaid body means and coupling member, said expander means and couplingmember having second coengageable tapered surfaces tending to urge saidcoupling member laterally inwardly in response to relative longitudinalmovement between said expander means and coupling member, the angle ofsaid first coengageable tapered surfaces to the axis of said body meansbeing substantially greater than the angle of said second coengageabletapered surfaces to the axis of said body means to release said couplingmember from said expander means in response to longitudinal forceimposed on said body means.

6. In apparatus to be disposed within and anchored, to

I a well conduit: bodymeans; slip ins-trumentalities carried by saidbody means and adapted to engage the well conduit to anchor the bodymeans therewithin against longitudinal movement in one direction;expander means slidable along said body means and adapteclto coact withsaid slip instrumen-talities to expand and holdsaid slipinstrumentalities against the well conduit; means for relativelyshifting said expander means and slip instrumentalitiesto expand saidslip instrumentalities against the well conduit; means for transmittinglongitudinal force directly from said body means to said expander meansI including a coupling member, said body means and coupling memberhaving first coengageable tapered surfaces tending to urge said couplingmember laterally outwardly in response to longitudinal movement of saidbody means in said one direction, said expander means and couplingmember having second coengageable tapered surfaces tending to urge saidcoupling member laterally inwardly in response to longitudinal movementof said body means in said one direction, the angle of said firstcoengageable tapered'surfaces to the axis of said body means beingsubstantially greater than the angle of said second coa well conduit:body means; slip instrumentalities carried by said body means andadapted to engage the well conduit to anchor the body means therewithinagainst longi tudinal movement in one direction; expander means slidablealong said body means and adapted to coact with said slipinstrumentalities to expand and hold said slip 'instrumentalitiesagainst the well conduit; means for relain response to longitudinalmovement of said body means in said one direction, the angle of one ofsaidcoengageable tapered surfaces to the axis of said body means beingsubstantially different than the angle of said other coengageabletapered surfaces to the axis of said body means to release said couplingmember from one of said means in response to a force imposed by saidbody means in said one longitudinal direction.

5. In apparatus to be disposed within and anchored to a well conduit:body means; slip instmrnentalities carried by said body means andadapted to engage the well conduit to anchor the body means therewithin;expander means slidable along said body means and adapted to coact withsaid slip instrumentalities to expand and hold engageable taperedsurfaces to the axis of said body means to release saidLcoupling memberfrom said expander means in response to longitudinal force imposed onsaid body means and exerted in said one longitudinal direction.

7. In apparatus to be disposed within and anchored to a well conduit: abody; slip instrumentalities carried by said-body and adapted to engagethe well conduit to anchor the body thcrewithin; expander means slidablealong said body and adapted to coact with said slip instrumentalities toexpand and hold said slip instrumentalities against the well conduit;hydraulically operable means for shifting said expander means along saidbody and slip instrumentali-ties to expand said slip; instrumentalitiesagainst the well conduit; means for transmitting longitudinal forcedirectly from said body to said expander means including a couplingmember having inner and outer tapered surfaces, said body engaging saidinner tapered surface, said-expander means engaging said outer taperedsurface, the angle of said inner tapered surface to the axis of saidbody being substantially greater than the angle of said outer taperedsurface to the axis of said body to release said coupling member fromsaid expander means in response to longitudinal force imposed on saidbody. I

8. In apparatus to be disposed within and anchored to a wellconduit: -abody; slip means carried by said body and adapted to engage the wellconduit to anchor the body therewithin; an expander slidable along saidbody and adapted to coact with said slip means to expand and hold saidslip means against the well conduit; a piston movably mounted on saidbody; a cylinder slidable along said piston and connected to saidexpander means; coupling means connected to said piston and disposedbetween said body and cylinder; said body and coupling means havingfirst coengageable tapered surfaces tending to urge said coupling meanslaterally outwardly in response to movement of said piston on said body;said coupling means and cylinder having second coengageable taperedsurfaces tending to urge said coupling means laterally inwardly inresponse to relative longitudinal movement between said expander andcoupling means; the angle of said second tapered surfaces to the bodyaxis being substantially less than the angle of said first taperedsurfaces to the body axis to release sm'd coupling means from saidcylinder in response to longitudinal force imposed on said couplingmeans by said body.

9. In apparatus to be disposed within and anchored to a Well conduit: abody; slip means carried by said body and adapted to engage the wellconduit to anchor the body therewithin; an expander slidable along saidbody and adapted to coact with said slip means to expand and hold saidslip means against the well conduit; a

piston movably mounted on said body; a cylinder slidable along saidpiston and connected to said expander means; coupling means connected tosaid piston and disposed between said body and cylinder; said body andcoupling means having first coengageable tapered surfaces tending tourge said coupling means laterally outwardly in response to movement ofsaid piston on said body; said coupling means and cylinder having secondcoengageable tapered surfaces tending to urge said coupling meanslaterally inwardly in response to relative longitudinal movement betweensaid expander and coupling means;

the angle of said second tapered surfaces to the body axis beingsubstantially less than the angle of said first tapered surfaces to thebody axis to release said coupling means from said cylinder in responseto longitudinal force imposed on said coupling means by said body; andreleasable retainer means connected to said piston and engageable Withsaid cylinder to prevent movement of said cylinder and expander means ina direction to expand said slip means.

1G. in apparatus to be disposed Within and anchored to a Well conduit: abody; slip means carried by said body adapted to engage the well conduitto anchor the body therewithin; an expander slidable along said body andadapted to coact with said slip means to expand and hold said slip meansagainst the well conduit; a piston on said body; a cylinder slidablealong said piston and connected to said expander; coupling meansconnecting said piston to said body; and releasable retainer meansconnected to said piston and engageable with said cylinder to preventmovement of said cylinder and expander in a direction to expand saidslip means; said cylinder having means thereon subject to pressure inthe well conduit to move said cylinder along said piston and saidexpander alon said body.

11. In apparatus to be disposed within and anchored to a well conduit: abody; slip means carried by said body and adapted to engage the wellconduit to anchor the body therewithin; an expander slidable along saidbody and adapted to coact with said slip means to expand and hold saidslip means against the well conduit; a cylinder connected to saidexpander; a coupling sleeve between said body and cylinder and connectedto said body, said sleeve including a piston along which said cylinderis slidable and also including a retainer element releasably engagingsaid cylinder to initially prevent movement of said cylinder andexpander in a direction to expand said slip means; said cylinder havingmeans thereon subject to pressure in the well conduit to move :saidcylinder along said piston and said expander along said body.

12. In apparatus to be disposed within and anchored to a well conduit: abody; slip means carried by said body and adapted to engage the wellconduit to anchor the body therewithin; an expander slidable along saidbody and adapted to .co'act with said slip means to expand and hold saidslip means against the Well conduit; a cylinder connected to saidexpander; said body having an expander surface thereon; said cylinderhaving a retractor surface thereon; a coupling sleeve between said bodyand cylinder including a piston along which saidcylinder is slidable,thrust elements engaging said expander surface and engageable with saidretractor surface, and retainer elements releasably engaging saidcylinder to initially prevent movement of said cylinder and expander ina direct on to expand said slip means; the angle of inclination of saidexpander surface to the body axis being substantially greater than theangle of inclination of said retractor surface to the body axis; saidcylinder having means thereon subject to pressure in the Well conduit tomove said cylinder along said piston and said expander along said body.

13. In apparatus to be disposed Within and anchored to a well conduit:body means; slip iustrumentalities carried by said body means andadapted to engage the well conduit to anchor the body means therewithinagainst upward movement; expander means slidable upwardly along saidbody means and adapted to coact with said slip instrumentalities toexpand and hold said slip instrumentalities against the well conduit;hydraulically operable means responsive to the pressure of the fluidwithin said body means for shifting said expander means upwardly alongsaid slip instrumentalities to expand said slip instrumentalitiesagainst the well conduit; means for transmitting upwardly directedforces directly from said body means to said expander means including acoupling member, first coengageable cam means on said body means andcoupling member tending to urge said coupling member laterally outwardlyin response to upward movement of said body means along said couplingmember, second coengageable cam means on said coupling member andexpander means tending to urge said coupling member laterally inwardlyin response to upward movement of said coupling member with respect tosaid expander means, said first and second cam means being soconstructed and arranged that one of said cam means exerts a greaterlateral force than said other cam means to release said coupling memberfrom one of said means in response to an upward force imposed on one ofsaid means.

14. In apparatus to be disposed within and anchored to a well conduit:body means; slip instrumentalities carried by said body means andadapted to engage the well conduit to anchor the body means therewithinagainst downward movement; expander means slidable downwardly along saidbody means and adapted to coact with said slip instrumentalities toexpand and hold said slip instrumentalities against the Well conduit;hydraulically operable means responsive to the pressure of fluidexternally thereof for shifting said expander means downwardly alongsaid slip instrumentalities to expand said slip instrumentalitiesagainst the well conduit; means for transmitting downward force directlyfrom said body means to said expander means ncluding a coupling member,first coengageable cam means on said body means and coupling membertending to urge said coupling member laterally outwardly in response todownward movement of said body means with respect to said couplingmember, second coengageable cam means on said coupling member andexpander means tending to urge said coupling member laterally inwardlyin response to downward movement of said coupling member with respect tosaid expander means, said first and second cam means being soconstructed and arranged that one of said cam means exerts a greaterlateral force than said other cam means to release said coupling memberfrom one of said means in response to a downward force imposed on one ofsaid means.

15. In apparatus to be disposed within and anchored to a well conduit: abody; slip means carried by said body and adapted to engage the wellconduit to anchor the body against upward movement therewithin; anexpander slidable upwardly along said body and adapted to coact withsaid slip means to expand and hold said slip means against the wellconduit; a piston movably mounted on said body; a cylinder slidableupwardly along said piston and connected to said expander; couplingmeans connected to said piston and disposed between said body andcylinder; said body and coupling means having first coengageable taperedsurfaces tending to urge said coupling means laterally outwardly inresponse to relative downward movement of said piston on said body; saidcoupling means and cylinder having second coengageable tapered surfacestending to urge said coupling means laterally inwardly in response toupward movement of said coupling means relative to said cylinder means,the angle of said second tapered surfaces to the body axis beingsubstantially less than the angle of said first tapered surfaces to thebody axis to release said coupling means from said cylinder in responseto an upward force imposed on said coupling means by said body, saidbody having a port therein for conducting fluid from the interior ofsaid body into said cylinder above said piston to urge said cylinderandexpander upwardly along said body and slip means.

16. In apparatus to be disposed within and anchored to a well conduit: abody; slip means carried by said body and adapted to engage the wellconduit to anchor the body against downward movement therewithin; anexpander slidable downwardly along said body and adapted to coact withsaid slip means to expand and hold said slip means against the wellconduit; a piston movably mounted on said body; a cylinder responsive tothe pressure of fluid externally thereof and slidable downwardly alongsaid piston by such fluid under pressure and connected to said expanderto shift said expander downwardly along said body and slip means;coupling means connected to said piston and disposed between said bodyand cylinder; said body and coupling means having first coengageabletapered surfaces tending to urge said coupling means laterally outwardlyin response to relative upward movement of said piston on said body;said coupling means and cylinder having second coengageable taperedsurfaces tending to urge said coupling means laterally inwardly inresponse to relative downward movement of said coupling means withrespect to said cylinder means, the angle of said second taperedsurfaces to the body axis being substantially less than the angle ofsaid first tapered surfaces to the body axis to release said couplingmeans from said cylinder in response to downward force imposed on saidcoupling means by said body.

17. In apparatus to be disposed within and anchored to a well conduit: abody; slip means carried by said body and adapted to engage the wellconduit to anchor the body therewithin; an expander slidable along saidbody and adapted to coact with said slip means to expand and hold saidslip means against the well conduit; a piston movably mounted on saidbody; a cylinder slidable along said piston and connected to saidexpander; coupling means connected to said piston and disposed betweensaid body and cylinder; said body and coupling means having firstcoengageable tapered surfaces tending to urge said coupling meanslaterally outwardly in response to movement of said piston on said body;said coupling means and cylinder having second coengageable taperedsurfaces tending to urge said coupling means laterally inwardly inresponse to relative longitudinal movement between said expander andcoupling means; the angle of said second tapered surfaces to the bodyaxis being substantially less than the angle of said first taperedsurfaces to the body axis to release said coupling means from saidcylinder in response to longitudinal forces imposed on said couplingmeans by said body; and releasable retainer means interconnecting saidbody and cylinder to prevent movement of said cylinder and expander in adirection to expand said slip means; said cylinder having means thereonsubject-to pressure in the well conduit to move said cylinder along saidpiston and said expander along said body.

18. In apparatus to be disposed within and anchored to a well conduit:body means; slip instrumentalities carried by said body means andadapted to engage the well conduit to anchor the body means therewithin;expander means slidable along said body means and adapted to coact withsaid slip instrumentalities to expand and hold said slipinstrumentalities against the well conduit; spring means disposedbetween and engaging said expander means and slip instrumentalities andtending to shift them in longitudinal direction away from each other tourge said slip instrumentalities toward a retracted position;hydraulically operable cylinder and piston means for relatively shiftingsaid expander means and slip instrumentalities against the force of saidspring means to expand said slip instrumentalities against the wellconduit; said body means having a side port for feeding fluid underpressure from the interior of said body means to said hydraulicallyoperable cylinder and piston means.

19. In apparatus to be disposed within and anchored to a well conduit: abody; slip means carried by said body and adapted to engage the wellconduit to anchor the body therewithin; an expander slidable along saidbody and adapted to coact with said slip means to expand and hold saidslip means against the well conduit; a piston on said body; a cylinderslidable along said piston and connected to said expander; couplingmeans connecting said piston to said body; and releasable retainer meansconnected to said piston and engageable with said cylinder to preventmovement of said cylinder and expander in a direction to expand saidslip means; said cylinder having a portion responsive to fluid pressureto slide said expander along said body and expand said slip means.

References Cited in the file of this patent UNITED STATES PATENTS2,187,482 Baker et al. Jan. 16, 1940 2,345,873 Hart Apr. 4, 19442,735,497 Brumleu Feb. 21, 1956 2,756,827 Farrar July 31, 1956 2,874,784Baker et al. Feb. 24, 1959

